In the field of packaging it is often desired to provide a packaging structure with a polymeric coating. Such polymeric coatings may impart durability, moisture resistance, and other useful properties such as heat-sealability. Recently there is increasing interest in using biopolymers for the polymer coating in such packaging structures. One popular biopolymer is polylactic acid (PLA). However, PLA presents challenges when used in an extrusion coating process, including adhesion to paperboard, heat sealability, and large scale edge weave and neck-in.